One of the intriguing things about integrative thinking is that it encourages the kind of paradoxical sense that is useful in life. That is why when we argue from first principles, we start in the middle and not at the beginning. Put another way, principles have to come from somewhere. So do beginnings.
We are about to start a practitioner training, a fresh beginning with new class. As a class, it will be a beginning, a group of people coming together for the first time. Yet it will not be a beginning for any of the individuals in the class (they all have histories that start before the class) and it will not be a beginning for the course (we've been working to prepare for it!). The first principle of interacting with people is that we always start in the middle.
The idea of first principles, of bedrock presuppositions that allow us to make sense of what comes after, is immensely appealing and often very useful. Arguing from principles means working from what is known and knowable to what is new with a certain degree of hope (if not certainty) that what is known will tell us something useful about what is new. Often we find that we have grabbed the wrong principles as we rushed out the door, and have to go back and find the ones we really wanted. Sometimes we have to dig into the back of the closet to find them.
The nature of training in integrative thinking is often a rummaging in closests or attics to discover old things that correspond in useful ways to new challenges. Because arguing from first principles means accepting that a course never starts at the beginning.